Mild summer slices smog

Riverside County residents are breathing easier, thanks to a
mild summer. "We're going to have a less smoggy summer than last
year, even if the weather should turn very adverse at this point,"
Sam Atwood, a spokesman for the South Coast Air Quality Management
District, said Wednesday.

A little more than halfway through the smog season, the number
of days when ozone levels soared to dangerous levels is one-third
the total at this time last year. Through Wednesday, Atwood said,
levels had reached the unhealthful range 15 times compared to 44
last year in the air basin that consists of western Riverside
County, southwestern San Bernardino County, Orange County and Los
Angeles County.

As well, the highest one-hour ozone concentration recorded this
year is well below any reached in 2003, Atwood said.

"We're well behind where we were last year in terms of the
number of unhealthy days, and the No. 1 reason is the cooler
weather we have been having this summer," he said.

After a hot May, when bone-dry, 100-degree heat triggered
massive wildfires in the parched chaparral east of Temecula and
north of Lake Elsinore, June gloom set in and stayed around a
while. After a seasonally warm July, typically torrid August is off
to a cool start.

Forecaster Robert Balfour for the National Weather Service in
San Diego said high temperatures in the city of Riverside averaged
84 in June, three degrees below normal, and 93 in July, one degree
below normal.

There were more 100-degree days in the typically cooler months
of April and May -- four -- than for all of June and July, when
there were three, Balfour said. In fact, June had no 100-degree
days.

However, it's not just the temperature that is reducing smog.
Atwood said the basin has had fewer periods when air is stagnant
and traps smog.

The primary ingredient of smog is ozone, a pungent, colorless
gas that impairs breathing and can permanently damage lungs. Those
most vulnerable to the effects of smog are the elderly and young
children, as well as people with heart and lung conditions. On the
worst days, smog cloaks the mountain skyline with a milky, gray
haze.

While factories contribute to smog, three-quarters of if comes
from cars and trucks. Most of it blows in from Los Angeles, then
cooks in the inland heat to form a toxic brew.

For the purpose of gauging health effects on Southwest Riverside
County, the air quality district relies on ozone readings taken in
Lake Elsinore, which has recorded one unhealthy day so far in
2004.

However, since April the district has had a temporary pollution
monitoring station in Temecula. Atwood said it was set up to test
the district's long-running assumption that Temecula ozone levels
are about half of Lake Elsinore's, and so far readings are
confirming that.

Those differences are reflected in daily air quality forecasts
issued by the district. Wednesday's, for example, predicted a peak
one-hour concentration of 0.05 in Temecula, compared to 0.09 in
Lake Elsinore.